title: Constitutive neutrophil apoptosis in culture is modulated by cell density independently of beta2 integrin-mediated adhesion.
abstract: Although inflammatory mediators modulate the rate of constitutive neutrophil apoptosis in vitro the effects of micro-environmental conditions have not been fully investigated. In this study, we demonstrate that the rate of constitutive neutrophil apoptosis is affected by the number of cells per unit surface area, with enhanced survival at high cell density. Furthermore, the presence of protein or serum in the culture medium also enhances neutrophil survival. These effects were independent of beta2 integrin-mediated adhesion and were not influenced by specific adhesion to extracellular matrix components. Thus, the rate of neutrophil apoptosis is fundamentally influenced by microenvironmental conditions and indicates that factors such as cell density and extracellular protein concentration must be considered when investigating mechanisms regulating inflammatory cell apoptosis in vitro.
authors.affiliation: Department of Medicine (R.I.E.), University of Edinburgh Medical School, Scotland, UK. s.hannah@ed.ac.uk
authors.forename: S
authors.initials: S
authors.lastname: Hannah
authors.forename: I
authors.initials: I
authors.lastname: Nadra
authors.forename: I
authors.initials: I
authors.lastname: Dransfield
authors.forename: J G
authors.initials: JG
authors.lastname: Pryde
authors.forename: A G
authors.initials: AG
authors.lastname: Rossi
authors.forename: C
authors.initials: C
authors.lastname: Haslett
mesh_terms: D000818:Animals; D017209:Apoptosis; D018821:CD18 Antigens / Q000378:metabolism*; D002417:Cattle; D002448:Cell Adhesion; D002452:Cell Count; D002478:Cells, Cultured; D006801:Humans; D009504:Neutrophils / Q000166:cytology* / Q000378:metabolism*; D012710:Serum Albumin, Bovine / Q000494:pharmacology
chemical_list: D018821:CD18 Antigens; D012710:Serum Albumin, Bovine